What wall switch are you talking about? IF YOU ARE IN THE UNITED kINGDOM YOU SHOULD HAVE NO SWITCHES IN THE BATHROOM OTHER THAN PULLCORD TYPE.
NEVER TOUCH ANY ELECTRICAL DEVICE UNLESS THE ELECTRICAL SUPPLY IS SWITCHED OFF. IF YOU DONT KNOW WHAT YOUR DOOING DONT TOUCH IT. YOU ONLY HAVE ONE LIFE LOOK AFTER IT.
PETE, July 2008